Soil use and management modify mycorrhizal interactions, but how these changes affect the growth and nutrition of crops under different contexts has been poorly studied. The objective of this study was to evaluate the effects of arbuscular mycorrhizal fungal (AMF) spore communities belonging to two no-till cropping systems (soybean monoculture and soybean-maize rotation), and uncultivated grasslands replicated at four locations along a regional geographic gradient on soybean mycorrhizal colonization and performance. At a regional scale, AMF spore richness was higher in uncultivated grasslands, intermediate in crop rotations, and lower in monocultures. Arbuscular mycorrhizal colonization in soybean roots was also higher in uncultivated soils but did not differ between no-tillage systems. Soybean growth was positively affected by AMF from uncultivated grasslands in comparison to control without AMF. Instead, there were no significant effects of AMF from no-till cropping systems. Foliar P concentration was lower in monocultures irrespective of AMF. At the local scale, patterns were highly variable and differed between locations. These results highlight the importance of scales for management decisions in agriculture and add further support for the context-dependent nature of mycorrhizal interactions.

土壤的使用和管理改变了菌根的相互作用，但是在不同情况下这些变化如何影响作物的生长和营养的研究很少。这项研究的目的是评估属于两个免耕种植系统（大豆单作和大豆-玉米轮作）的丛枝菌根真菌（AMF）孢子群落的影响，以及沿区域地理梯度在四个位置复制的未耕种草地大豆的菌根定植和表现。在区域范围内，AMF孢子的丰富度在未耕种的草地中较高，在轮作中处于中等水平，而在单一栽培中较低。在未经耕种的土壤中，大豆根中的丛枝菌根定植也较高，但在免耕系统之间无差异。与没有AMF的对照相比，未经耕种的草原的AMF对大豆的生长有积极的影响。相反，免耕种植系统对AMF的影响不大。不管AMF，单培养中的叶面P浓度都较低。在本地范围内，模式变化很大，并且位置之间存在差异。这些结果突出了农业管理决策量表的重要性，并为菌根相互作用的上下文相关性质提供了进一步的支持。